Back-up post



R. D. MARTIN.

BACK-UP POST. APPLICATION mm APR. 18, 1921.

Patented Apr.

Svwevyto'c Z 721 UNITED STATES PATENT OFFICE.

ROBERT DRURY MARTIN, OF HULL, TEXAS.

BACK-UP Pos'r.

. To all whom it mag concern:

.Be it known that I, ROBERT D. MARTIN, citizen, of the United States, residing at Hull, in the county of Liberty and State of Texas, have invented certain new and,

. useful Impr vements in Back-Up Posts; and .I do declare the following to be a type of drilling rotary such as is used on a derrick platform for screwing and unscrewing pipe sections. 7

' Devices of the above named class are used for {holding a pipe sectionand the wrench or tong which it carries, against rotation in one direction, while the rotary on the derrick platform which is connected with the adjacent section of pipe, rotates this section in an oppositedirection in order to unscrew the two sections of. pipe. The common. form of back-up post is a onep'iece structure and experience with it has brought out the-fact that when the handle of the wrench is engaged with, considerable diificulty is experienced in disengagin it fromrthe post and section of pipe to which it is connected, owing to the fact that the piping tends to hold and practically lock the handle ofthe wrench very tightly against the post.

In view of-the foregoing circumstances and difficulties, I have devised and intend to employ an extremely novel and new kind of a back-up post of extreme simplicity which will permit the handle of the wrench which engages it to be easily and readily disengaged from it'aiter the pipe lengths Specification of Letters'1 at ent. i Patented Apr. 11, 1922. Application filed- April 18, 1921. SerialNo. 462,422.

handle which it engages, to be released therefrom without necessitating rotation of the post itself, which rotation is hindered to a very great extent, by the tendency of the pressure of the handle against the post, to bind the latter tightly in its receiving socket on the rotary.

Other objects, features, and constructional advantages of the invention will. become apparent during the course of the following description.

In the accompanying drawings forming a part of the specification and in which like numerals are employed to designate like parts throughout the same:

Fig. 1 is a perspective view of a back-up post constructed in accordance with this invention, the same being shown in use.

Fig. 2 is an enlarged side elevational view thereof showing the retractable abutment and other parts in the position they assume when they are in a partially inoperative position.

While it may not be necessary, it is thought advisable to enter at this point, a generaldescription of the device shown in Fig. l with which my improved back-up post isassociated as this will enable the reader to obtain a better and a clearer understanding of the invention. To this end, I have shown a erilling rotary A or conventional construction, the jaws B of which are intended to be clamped on the lower secticn of piping C to rotate this section with respect to the upper section D which is held stationary by means of my improved back-up post and wrench G of usual form. The rotary, among other things includes a raised socket E which serves to receive the usual one-piece back-up post. In addition to these parts, other details are dis closed, but need not be referred to here.

The foregoing details constitute no part of this invention. The invention resides, as before indicated, in the provision of a novel and newback-up post to take the place of the usual one-piece post vor sectional post heretofore employed. Referring to the improved device by numerals l designates the post which is designed to be arranged in the socket E as shown in Fig. 1. Construing broadly the additional details of construction to follow, it may be said that this post carries a thrust receiving device 2 which in its preferred form, is in the form of a laterally and upwardly curved integral arm. which terminates at a considerable distance above the upper end'of the post. The latter also carries a retractable abutment which is designed to be engaged by the handle of the wrench or tong G as shown connected with the piping C. lVhile this abutment may be connected with the post in any other way, it is preferably pivotally connected thereto, as indicated at 4C. WVhen this abutment is in retracted position, the handle of the wrench which is bearing and is locked against it, can be easily and readily released therefrom. In order to retain the abutment in vertical alignment with the post, thatis, in operative position, I make use of novel holding means which, by preference, is in the form of a toggle 5, ar-

' ranged between the upper ends of the abutment and thrust receiving arm the same having the outer ends of its links pivoted to these parts as shown. Since it would otherwise be rather difficult to break the joint of the toggle, I prefer to employ novel means for doing this and obviating the necessity of employing a separate hammer or the like for the purpose. The means employed comprises a handle or lever 6 which is pivoted in between its ends near the upper end of the arm 2, being provided on its other end with an enlargement 7 forming a hammer, the latter being disposed beneath and rather close to the aforesaid joint of the toggle so that when it is brought against one of the links as indicated in Fig. 2, the iinks'will be moved to the ineffective position therein shown. To increase the rigidity of the device and to provide means for automatically returning the toggle to its effective position by removing the inner end of the lever upwardly, I equip the ham.- mer 7 with a yoke 8, which has the additional function of a guide for the hammer to insure effective engagement thereof with the toggle for breaking the joint of the latter.

The operation of the device is as follows: assuming that it is desired to disconnect the pipe sections G and D by unscrewing them,

it will be seen, as shown in Figure 1, that the jaws B of the rotary A are engaging lower pipe section C while the pipe wrench G is engaged with the upper pipe section D. Now, by setting the rotary into action, both pipe sections will be turned as a unit, until the handle of the wrench is brought against the abutment 3 of the back-up post. As this abutment is held rigid by the toggle,

it will'act like the ordinary back-up post,

that is, will prevent further rotation of the pipe'section D. It is obvious that as long as the pipe section Dis held against rotation and the section C sections will become disconnected upon a continued rotation of the section C by the rotary, As soon as the sections of pipe beis rotated. the two ting the abutment to become retracted and enabling the wrench handle to be easily and readily releasedtherefrom without necessitating hammering of the same as is usually necessary to separate it from the ordinary back-up posts. In Fig. 21 have shown these.

parts in a partially ineffective position which permits the above result to be accomplished under such circumstances. 'How ever, I wish it to be understood that the position of the parts shown is not limiting as the abutment can bemoved much further inward toward the arm 2 as is necessary or desired. In order to render the parts'op erative, it will be necessary to swing the lever 6 in an opposite direction to bringthe connecting portion of the yoke with force against the upper side of the toggle link which it engages.

From the foregoing description, it will be seen that I have perfected an extremely advantageous and effective back-up post which will enable it to be removed from its socket in the rotary or permit the handle end of the wrench to be disengaged from it with extreme ease. I wish to direct attention to the fact that in order to accomplish this end, it is unnecessary to rotate the device as must be done with one back-up post with which I am familiar. As before pointed out, it is very difiicult to rotate such posts because of the extreme strain and weight asserted against them by the tendency of the pipe sections to lock the wrench handle against them and cause binding of the post in the socket in the rotary. This is an extremely important feature and advantage which my improved construction possesses over prior devices for similar purposes. These and other advantages and features of the invention, have, no doubt, become apparent from the foregoing description and drawings. 1

While I have shown and described my device as being especially advantageous for enabling pipe sections tb be unscrewed, I wish it to be understood that it will serve equally well to permit the sections; to be screwed together. Furthermore, the device will serve effectively to enable the sections of long well drilling tools to be connected and disconnected as'is obvious.

I wish to point out here that although I have shown and described my back-up post for use in connection with the particular type of rotary shown, I do not Wish to be limited to using the same with this kind of a rotary since it can well be connected with various other kinds of similar devices. For instance, it may be connected with that type of rotary wherein the back-up post is connected to the rotary table instead of to the base as shown. Furthermore, while I have not shown it, I wish it to be understood that in many instances, the conditions are such that it will be neceessary to employ an additional wrench or tong for connection to one of the sections of pipe and anchor this tong against movement to hold the section of pipe to which it is connected stationary.

The form of the invention herein shown and specifically described is taken as a preferred embodiment of the invention. However, I desire it to be understood that many minor changes within the scope of the sub joined claims may be resorted to.

I claim:

1. A device of the class described com prising a post, a retractable abutment carried thereby, and. means for holding the abutment in operative position, being releas able without necessitating rotation of the post.

2. The structure set forth on claim 1, together with a thrust device fixed with respect to said post, said holding means being disposed between the latter and thrust device.

A device of the class described comprising a post, an abutment pivoted to the upper end of the latter, a thrust device carried by the post, and a toggle disposed between the latter and thrust device.

"I. A. device of the class described comprising a post, a. curved laterally extending thrust receiving arm carried thereby and extending a considerable distance above the upper end thereof, a retractable abutment carried by the post, and holding means therefor arranged between it and said arm.

5. The structure set forth in claim 4;, said abutment being pivotally mounted on theupper end of said posts and having its upper end disposed in an approximate horizontal plane with the upper end of said arm, said holding means being a pair of toggle links,

(3. 'A device of the class described comprising a post, a retractable abutment associated therewith, a thrust receiving device, a toggle arranged between the latter and abutment for holding the abutment in operative position, and a hammer pivotally mounted on the thrust device for acting on and breaking the joint of the toggle.

7. A device of the class described comprising a post, aretractable abutment associated therewith, a thrust receiving device, a toggle arranged between the latter and abutment for holding the abutment in operative position, a hammer for acting on the joint of the toggle. and a yoke carried by the hammer for rendering the toggle effective.

8. A device of the class described comprising a post equipped at its upper end with an integral laterally and upwardly directed thrust receiving arm, an abutment for a wrench handle pivoted to the upper end of said post, hr ving its upper end arranged in a horizontal plane with the upper end of said arm, toggle links arranged between and pivoted to said abutment and arm, a lever pivoted between its ends on the latter, a hammer on the inner end of the lever for striking the joint of the toggle links, and yoke carried by the hammer for returning said links twoperative position.

In testimony whereof I have hereunto set my hand.

ROBERT DRURY MARTIN. 

